Dynamic Parameters. You'll want to get all your report designers up on this topic.

When you create a dynamic parameter in a Crystal Report, and then publish it to the Enterprise, you are creating a Business View, with all it's underlying necessary layers. Dynamic Parameters exist to be able to use the same LOV (a list of current customers) from a database for more than one report. These dynamic parameter LOVs act like a mini report that runs against the database and gets the current values for selection, then the selection(s) are used to run the overall report.

So I create a report, and in it I create a dynamic Customer LOV. When I save it, the Enterprise creates a Data Connection (DC), Data Foundation (DF), Business Element (BE), Business View (BV), and the list of values is built on the Prompt Group. So, my Business View Manager, Repository Explorer will show (in the default Dynamic Cascading Prompts folder):
Customer_DC
Customer_DF
Customer_BE
Customer_BV
Customer - Prompt Group
Customer (the LOV)

The idea is that next time I create a report and need a customer parameter, I select the existing dynamic group. If the report designer is unaware of this, and next time they create a new report that needs a customer LOV, they creates a new dynamic LOV "Customer", when saved to the Enterprise, it repeats the above. Since repository objects must have unique names, you will now have additional items something like:
Customer 2_DC
Customer 2_DF
Customer 2_BE
Customer 2_BV
Customer 2 - Prompt Group
Customer 2 (the LOV)

So you can see how that folder will get filled with duplicates pretty quickly. Which ones were created and used in which reports? Have to open the report in Crystal Reports, open the parameter for Edit and verify the LOV name (_2, _3, _4, etc). If you do in fact discover there are dupes, you can change it to a single one for all reports using a dynamic LOV, re-save them to the Enterprise, then delete the dupes in the BVM.

You've already discovered how to use the BVM to update the data connection to include/save the database credentials. The only other common issue is sometimes the LOV rights need to be changed in order to allow users to "Edit" the LOV (select different values in the LOV). You'd have to run the report as an end user, not the admin account or the report designer account to verify that works.

Another item of note is that these dynamic LOVs are run by the Report Application Server (RAS), regardless of which viewer you are using.

The Business View Manager administration guide has more information on the subject.